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overheating problem

Posted By: Dave Scott

overheating problem - 05/19/15 04:33 AM

Ok, so anytime I spend 30 minutes or more in stop and go traffic, my radiator boils out. Got a new cap, didn't help, replaced the a/c fan, didn't help, replaced the thermostat, didn't help, replaced the fan clutch, didn't help, I think my belt might be a little loose, so I'm gonna tighten that next, my temp sensor never reads above normal. I don't understand what's going on. One thing I did notice is that there is no distinctive cold to hot change when touching the upper radiator hose when the thermostat should go from closed to open, but I only tested it immediately after installing it and haven't had time to do it again. Thermostat is easy and cheap, no biggie. But does anyone have any other ideas what could be happening?
Posted By: Peabody

Re: overheating problem - 05/19/15 05:45 AM

Not sure what to make of it. Seems you've covered the basic parts already. The replacement thermostat could be bad. You can pull it and drop it in boiling water to make sure it opens. I had a similar problem a few times.

One time I did some work on the engine and reinstalled the t-stat upside down (stupid, I know). Seemed to work fine on the road test, but quickly started to overheat when I got stuck in traffic and stayed hot after. That showed up on the temp gauge. I gimped it home real quick with the windows down and the heater blasting on high... in the middle of the summer. <img src="/forums/images/graemlins/scared.gif" alt="" />

I had the ground wire connector on my electric fan fail (poor connection that torched the connector and wire). The fan stopped and the temp gauge read high every time I came to a stop... but it cooled off quick after I had the vehicle moving again. So I gimped it home by avoiding every stop light and "California stopping" at every stop sign on the way back... <img src="/forums/images/graemlins/shiner.gif" alt="" />

The last incident, which happened many years ago, involved coolant puking out of the overflow tank on my Chevy Sprint after driving for a short period of time. I only noticed it after I had stopped and smelled the hot coolant, which had blown all over the engine compartment. It never showed on the temp gauge unless the coolant level got pretty low in the radiator. It turned out to be a blown head gasket that caused a cylinder to pressurize the cooling system via the adjacent coolant passage. It was far more pressure than the radiator cap could handle, thus forcing coolant out of the radiator and the overflow... until there wasn't enough coolant left to blow out. Then it just blew out the residual in the reservoir and started to overheat. I didn't bother fixing that one. Instead, I topped off the coolant, drove it to a gas station next to the local Ford dealer, cooled down the engine and topped off the coolant again. Then I drove it to the dealer and traded it in for a new Ford Ranger. It helped to do the trade just before closing time. The sales people were more interested in going home than inspecting the 3-cylinder "beast"... <img src="/forums/images/graemlins/smile.gif" alt="" />

I don't think the AC fan would have been the culprit. It should only run when the AC is on. The clutch fan should be sufficient to cool the system at idle, as long as it is spinning normally at idle. Is this a problem that only occurs with the AC on?

I can't think of or have experienced anything else that might be suspect. Perhaps someone else has a thought? I'm curious to hear what it turns out to be...

<img src="/forums/images/graemlins/patriot.gif" alt="" />
Posted By: Dave Scott

Re: overheating problem - 05/19/15 06:36 PM

It steams out with the a/c off, boils out with the a/c on. Gonna switch the thermostat again, I read somewhere a full 44% of thermostats made are faulty to some degree. It's like 5 bucks so, no biggie. But I really hope I don't have a problem I read about another forum poster having years ago - a blockage in the cooling system.
Posted By: 4x4Wire

Re: overheating problem - 05/23/15 04:54 PM

Water pump or radiator are two likely points of problem. Check the cooling fins on the radiator as they do oxidize and loose ability to disappear heat. This is common in coastal or northern climates where you have a build up of salts.
Posted By: Tommychu

Re: overheating problem - 06/08/15 05:35 PM

These Mazda lumps tend strongly toward mystery overheating when the HG fails too. It's an easy thing to test anyway, I like to use those coolant hydrocarbon testers with the indicator fluid but just starting it up with the rad cap off will tell you right away if it's really bad.
A PO may have used stop-leak too. Having a layer of wax through your water jackets in Texas heat would definitely cause issues.
Also, I don't mean to sound like a jerk but it sounds like you're engaging in shotgun diagnostics. All the parts you've replaced that didn't fix the problem were pretty easily testable. You'll save yourself a lot of money if you do a little poking around before ordering parts.
Posted By: bombardj1

Re: overheating problem - 06/09/15 04:46 PM

I would pull the thermostat then put the housing back on, see if there's flow, if not I would think radiator blockage or the water pump.
Posted By: Dave Scott

Re: overheating problem - 06/10/15 06:25 PM

Thanks for the replies, I think I figured it out. The radiator is steaming out between the metal and plastic parts, the a/c fan from the junkyard isn't working at all, will check the fuse first, if it's fine, I'm just going to buy a new one instead of pulling another from the junkyard, and I haven't tested the thermostat yet, but I will do that this weekend, if its bad, I'll get another one. Thanks again. Trying to find an all metal radiator under $180, but no luck so far, any tips?
Posted By: Everet

Re: overheating problem - 06/11/15 02:55 AM

Didn't look to far and found this:
2 row Aluminum radiator
At that price it looks pretty good and it's 2 row!
Let us know what you think.
Everet
<img src="/forums/images/graemlins/patriot.gif" alt="" /> <img src="/forums/images/graemlins/cheers.gif" alt="" /> <img src="/forums/images/graemlins/kewl.gif" alt="" /> <img src="/forums/images/graemlins/kewl.gif" alt="" />
Posted By: 4x4Wire

Re: overheating problem - 06/11/15 08:51 PM

While an aluminum radiator is good for rapid heat dissipation, take a close look at your mounting points. I would mounting using a firm rubber cushion rather that metal to metal contact at the mounting points. Aluminum is noted for developing stress cracks when rigid mounts are used.
Posted By: bombardj1

Re: overheating problem - 06/13/15 06:15 AM

When you changed the clutch fan was it a new one? If not is the bi-metal spring still on the front? I had one break and the truck would over heat.
Posted By: DennisThompson

Re: overheating problem - 06/14/15 05:00 PM

When I had my Sportage I always used factory Kia thermasats, when I tried a parts store one it never worked right. The problem you first described sure sounds like a thermasat though.
Posted By: Tommychu

Re: overheating problem - 06/14/15 05:15 PM

Quote
While an aluminum radiator is good for rapid heat dissipation, take a close look at your mounting points. I would mounting using a firm rubber cushion rather that metal to metal contact at the mounting points. Aluminum is noted for developing stress cracks when rigid mounts are used.

That rad does make use of the factory rubber isolators, so it should be fine aside from the general dodginess of Chinese eBay performance parts.

If there's a leak between the tank and core of the rad, your HG just became a prime suspect. Plastic-tanked rads usually don't fail there (you generally will get cracks in the middle of the tank near the neck) unless you're getting pressure spikes, as you would from each combustion event injecting a little bit of blazing hot gas into the cooling system. And since Kia cheaped out on these engines and used a graphite HG (graphite is okay on an all-iron or all-aluminum engine but bad news on an engine with dissimilar metals) rather than the MLS style that Mazda originally used on nearly all the B and F series engines, they're a really common failure point and the layout of the ports between block and head mean that you rarely see the classic 'chocolate milk', it's almost always the tough-to-detect transfer between the combustion chamber and water jackets wreaking havoc on your cooling system (and catalytic convertor, those things don't like being doused in glycol).
The coolant hydrocarbon testers I mentioned earlier are fairly cheap (I think mine cost me like 30 Canadian pesos) and easy to use, and a head gasket is the kind of issue you want to either confirm or rule out ASAP.
Posted By: Dave Scott

Re: overheating problem - 06/21/15 04:53 AM

Well, put a new a/c condenser fan on and so far, so good. But new issue, engine rattled and died, checked the oil and there was only a teeny tiny drop at the end of the dipstick, so, it was time for an oil change anyway, so I dumped it and replaced it, new filter, etc. When I poured the old oil into the new oil's empty jug, I see I get 4.5 quarts. So how on earth is my dipstick not showing this when the engine is hot. Checked level after oil change and dipstick shows full. So...??? Maybe it was crinkled up inside the tube and didn't reach all the way in, I don't know. Also changed spark plugs and, as always, oil in rearmost chamber. That's nothing new, I've had 3 Sportages and they've all had that issue, but never seen no oil on the dipstick. Oh, and as far as the aluminum radiator thing? I was actually looking for one made of copper, not too fond of aluminum, but the abuse it's going to see soon just makes me think a tougher metal is in order. Cheapest one I can find is a specifically designed performance radiator for about $205.
Posted By: Dave Scott

Re: overheating problem - 07/02/15 04:18 PM

Someone mentioned this above, not sure if I was just talking too much while installing, but I feel like a huge noob at this point. I have changed multiple thermostats on Sportages. I've owned 3 and had to do this multiple times on each. Somehow, not paying attention or whatever, I INSTALLED IT UPSIDE DOWN!!!!! So, turned it over, now the cheap gasket is leaking, will replace today.

Edit---nevermind, I'm an even bigger idiot because I thought I put it in upside down!!!!!!! Ugh... It was just a bad thermostat. Like I thought originally... <img src="/forums/images/graemlins/shiner.gif" alt="" />
Posted By: Dave Scott

Re: overheating problem - 07/05/15 04:35 AM

Nope, still have the same issue. It wasn't pushing out the cap and overflow tank with the a/c on because it was pushing out the thermostat housing due to the bad gasket. So, there are only a few options left - either the water pump is not circulating the coolant, the head gasket is blowing gas into the water channels, the radiator is too gunked up to actually cool the coolant, or lastly, there is a blockage in the block somewhere. Ok, so, the water pump, I can test that by removing the thermostat. I will do this asap. I really don't think the issue is the head gasket for two reasons - it only happens when the a/c is on (and yes, the condenser fan works great) and, I have zero water from the tailpipe. As far as the radiator being gunked up? Not really any way to test that, that I know of, just replace and run. If its a blockage in the block, I may be able to tell when I test the water pump. Or maybe not. Guess we'll find out. <img src="/forums/images/graemlins/shiner.gif" alt="" />
Posted By: Lou

Re: overheating problem - 07/20/15 12:33 PM

Quote
... So, there are only a few options left -... the head gasket is blowing gas into the water channels,...

WHen this happens, you can usually see exhaust bubbles escaping the radiator(when filled to the rim) . and tHere are gas analysers that would indicate presence of combustion gasses...
Zero water from the exhaust is NOT a sign of anything....each gallon of burned fuel feeds the exhaust pipe with lots of water (MUCH more than a gasket leak) as a combustion byproduct...and you never see it in liquid form except when the exhaust pipe is cold and it condenses in the pipe....
Posted By: promodmerc

Re: overheating problem - 10/01/15 04:52 PM

I'm now experiencing the same issue. My radiator has been leaking slightly between the core and tank for a 4 months or so. yesterday at lunch time I noticed my temp gauge was reading 210 and it was only in the mid 60's. As soon as I came to a stop it was steaming out.

I put a gallon of water in before leaving work hoping to make it home and only made it about 10 miles. When I saw it reaching 220 I hit the next exit and puled into a business parking lot and called my roadside assistance for a tow home.

Weird thing was my overflow tank was full when I checked it after parking. I grabbed a towel I had and Carefully removed the radiator cap. Steam was all that came out. Makes me wonder if my thermostat is stuck shut.

Only 1/2-3/4 mile after leaving work it had got to 200 but went down to 190-195 so the t-stat must have opened but may have closed.
Posted By: Dave Scott

Re: overheating problem - 10/01/15 05:28 PM

Ok, now I have definitely had that issue before. Basically exactly how you described. I replaced only the radiator and had no more issues. Your thermostat is probably ok, but they are so cheap I wouldn't recommend not replacing it also. I think the water in the rad turned to straight steam because it's not under any pressure if it's steaming out like that, plus you may have needed more than a gallon if the water that normally sits in the block was also gone. With only a partial fill, it will turn to steam faster and steam out of the gap quicker.
Posted By: Dave Scott

Re: overheating problem - 10/01/15 05:36 PM

Now, I'm not sure if I mentioned it above, scanned over and didn't see it, but I drove to south Dakota and back in July and only had to top off the radiator every 2-400 miles and not adding much, but I drove 7 miles in city traffic taking my daughter to school last week with the a/c on for only the last 2 miles and it boiled out about a half gallon. Anyway, I got my new radiator, CSF 2 core copper and brass, no plastic at all. Installing this weekend as soon as I hook the rad hoses to some pvc and stick them in a bucket of water to test the water pump.
Posted By: promodmerc

Re: overheating problem - 10/01/15 05:55 PM

Originally Posted by Dave Scott
Ok, now I have definitely had that issue before. Basically exactly how you described. I replaced only the radiator and had no more issues. Your thermostat is probably ok, but they are so cheap I wouldn't recommend not replacing it also. I think the water in the rad turned to straight steam because it's not under any pressure if it's steaming out like that, plus you may have needed more than a gallon if the water that normally sits in the block was also gone. With only a partial fill, it will turn to steam faster and steam out of the gap quicker.


Picking up the T-Stat, gasket & new cap from NAPA after work. KIA dealer would had to order the T-Stat & gasket. I don't have time to wait.

New radiator should be here Friday from Rock Auto. I wanted an all aluminum but the place I was looking at was out of stock. I need my Sporty up & running this weekend.

Didn't think about the block being low or empty or plain water having a lower boiling point.

Last thing I might need is a gallon of coolant. I have about 1-1/2 to 1-3/4 50/50 at home. I buy a gallon of straight and a gallon of distilled water and mix myself. Much cheaper that way.
Posted By: Dave Scott

Re: overheating problem - 10/03/15 01:59 AM

Ok, got the new radiator in. More of a pain in the @$$ than I remember. Changed the oil, added some transmission fluid as some leaks when you disconnect to swap the radiator, then I overcharged my a/c. Got no boiling out on the way home, about 45 miles, but I did see some coolant on the top of the radiator near the cap. I had tested the water pump and it sprayed coolant everywhere, so I hope that's all it was. The a/c compressor is now clicking on and off constantly. Can I just evacuate some R134 until it's back to normal?
Posted By: promodmerc

Re: overheating problem - 10/05/15 04:52 PM

Got mine fixed Saturday. I had the old radiator out in just over an hour. (I have a 5 speed so I didn't have to deal with the trans line connections) Took more time going back in as I was being very careful not to damage the new one.

I also replaced my lower radiator hose as I had forgot I had cut it a little jagged when I replaced it last year when I replaced the timing belt, water pump & components.
Posted By: promodmerc

Re: overheating problem - 10/07/15 05:10 PM

Well now it seems the fan clutch is bad too. Got one ordered. In the future I might add an electric fan, just don't feel like messing with that right now.

I had thought hard about a flex fan but a friend talked me out of that idea.
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